London Girl,
I was in exactly the same position as you. I was same age, worked in the City and had about 30k too. I figured just what esvdx has said and now I'm getting towards the last few months of flying and not regretting my decision. I will have my fATPL and only be in a small amount of debt. Maybe 5/6k max... Nothing I've seen so far has led me to believe I will have gained much by doing the integrated course.
B